Unfortunately, I haven't played with a 'vanilla' copy of DA:O probably since it released. I'm addicted to installing mods to games like this lol. I made it through NMM, without any 'cheats' of sorts, but I'm sure the mods I used gave me quite an advantage at some points.

I made it through the game using only Leliana and...Sten? (Is there one more party member? FML It's been too long lol). Leliana went with dual daggers, Sten used a 2h sword, and my character was a bow user. Killing and/or weakening enemies before they get to you is definitely a sure-fire way to get past those more difficult parts.

I'd also pay serious attention to what tactics your party members are using. I had a mod that seriously increased not only the tactics slots I had per character, but also what you could do, so after a few trials and errors I had basically perfect setups on my chars. Barring that though, if your party seems like it just isn't pulling the DPS it should, or they're too squishy, I'd take a look at those first.

There's also your gear. This game is definitely gear-dependent, and if you have shoddy gear, NMM is going to rape you, straight up. Even my mods couldn't save me on that point lol. I reloaded probably a hundred times or more before finally getting through it.

Sorry lol, I'm sure this isn't much help at all. It's been about 2 years or more since I last played DA:O, and I have a shitty memory >.>

Long time ago now but I remember using 3 mages I think, all with heals and (can't remember the class name) a really tanky 4th, with a taunt. The mages specs were split between slows, heals and AoE damage, with very little single target damage.

If I remember right Cone of cold, on 2 mages gives a truly insane amount of kiting and I think there is a spell called haste? Or something like that with a move speed increase.

Anyway the idea of the comp was slow steady kiting, did little damage and require you to have the game nearly perma paused so you could keep targets slow and keep the team in the right position. If a remember just runs off randomly on nightmare is probably dead. Also If I remember this combo fairs very poorly on fights where you get flanked. Also I had a certain way to handle ranged enemies but for the life of me can't remember the spells(maybe used a rouge?)

3 Mages and a Tank for me. Make your main a mage and spec into heals. Get Wynne ASAP, so she doesn't spend her talents on crap and make her be damage, etc. Get that Spirit Chains or w/e (been so long) the CC that damages and CCs same time. Just make use of combos with the mages. Try not to automate the gameplay too, pause often and do stuff yourself.

For my party, I used tank warrior for the main character, archer Leliana, Wynne, and Morrigan specced into spirit healer.

This is literally the easiest way to beat the game, because if built right, a main character tank warrior is the most powerful character in the game and can solo anything. Lemme put it this way, when fighting the Archdemon, my entire party except for my main character died at 50%. I then proceeded to make the Archdemon my bitch over the next 20 minutes.

And I just started writing up a guide for my build, but I remember that I emailed this build to a friend like a year ago. So imma just copy and paste.

"Attributes:

Put every point into strength until 43

Put points into constitution until 20, you will have a modified constitution of 36 at the end of the game.

Put ALL remaining points into dexterity.

Make sure to do the circle of magi tower first, and don't miss any attribute increases in the fade. You will get several attribute increases there, so don't put too much into con or strength beforehand, you want to hit exactly 43 and 20.

Gear:

Main armor: Knight commander's plate. Costs 27 gold, bought from the used goods vendor outside of Orzammar. Requires Templar, gives 40% magic resist. This is the most important piece of gear in the game.

Off set armor: Wade's superior dragonbone. You get this from a side quest, make sure to always spend the maximum amount of money on it to get the best version.

Helm: Juggernaut helm is what you want for most of the game. You get it from a side quest in the brecillian forest. You must fight several revenants to get it. In the last battle you will replace this helm with one called corruption. Corruption drops off a darkspawn general in Denerim during the final battle. It is a tank's dream, providig tier 7 armor, +5 dexterity, and 75% spirit resistance, which is great for the Archdemon.

Rings: Key to the city. You get this from a ridiculously easy side quest in Orzammar. This ring provides +4 to all attributes and 4% magic resist. The other ring is Lifeward, you buy it from a dwarf in Orzammar for around 80-100 gold. This ring provides +10 con and a few other minor bonuses.

Amulet: The spellward. Bought from Bodhan Feddic in your camp, it costs 87 gold. This provides 30% magic resistance and 10% chance to dodge attacks, this is the second most important piece of gear in the game.

Belt: Andruil's blessing. Bought for 106 gold from the vendor in the circle tower. This belt provides +2 to all stats and some nature resist.

Shield: Howe's shield. Found in Howe's estate, provides 18 defense, overall the best shield in the game despite the penalty to willpower.

Weapon: Bloodline. This axe drops from the corrupted spider queen, a boss in Ortan Thaig in the deep roads. Its tier depends on what level you are when you get it. It will likely be T5 or T6. When you reach level 19 save your game and sell this weapon to Bodhan Feddic in your camp. Leave the area, travel somewhere, and re-enter the camp. Check his shop, and look at the tier of Bloodline. There is a chance it will have changed to T7. If it didn't, repeat the above steps until it does. Alternatively you could attempt to reach level 19 or 20 before killing the spider queen.

Alternative weapon: You may not get Bloodline until late in the game. To hold you over until then, pick up Aodh. This axe drops from an enemy that you kill in a side quest in Denerim. This is available as soon as you leave Lothering, and it's a very nice T6 axe that you won't replace until Bloodline. I'd recommend looking up a guide for the specifics of the quest, the dragon age wiki is great for this.

Enchantments: +8% magic resistance x2 and 1 +10% magic resistance. You get 40% from the Knight commander's plate, 30% from the spell ward, 26% from enchantments, and 4% from key to the city. This totals up to 100%!

Talents: Spec Templar for your first specialization, the other one is up to you, both reaver and berserker are good choices for their passives, though their active abilities suck.

Try to get shield wall as soon as possible, and always keep it on. It actually has no penalty due to being bugged. After that get precise striking and threaten, and always keep them on. From there max out the weapon and shield tree. After that take whatever looks useful, but make sure you eventually get all templar abilities.

This build is a little underpowered early game, but it gets significantly better with each piece of gear, and each important ability that you pick up. The endgame has virtually no difficulty with this build, even on nightmare mode."

For other party members, I used Leliana, Wynne and Morrigan for various reasons. I liked having a rogue, and melee rogues are, imo, too squishy for nightmare mode, and Leliana is better than Zevran at being an archer. I really like Leliana's songs for the mana regen, which is great with two mages in the party. One of the best abilities in the game that you want to pick up asap with Leliana is scattershot. It has absolutely bat shit crazy AOE, and it stuns everything while also dealing significant damage. It's the best rogue ability in the game imo. For Leliana, you just want as much damage stats as possible, as well as a good bow. Some con doesn't hurt, but it's not required. For the mages, you want fireball, and you want heals. You want to get Morrigan spirit healer asap, and pick up heal, and all of the spirit healer stuff on both mages. It's OP.

Basically, in fights against large groups, you want to stunlock as much as possible. Open up with Leliana using scattershot, then right before the stun ends, use fireball from a mage, then before the enemy can get up, fireball again, then use holy smite from your warrior. If you time it right, you get lots of free attacks on the enemies. This is sort of my generic strategy for any fight once I have these abilities. After you holy smite, run in with the warrior, taunt, and then just clean up. Even if a fight isn't close to over, as long as you micro manage your AOE abilities and your healing, this group comp can basically outlast anything.

Note: You can get a little better gear than what I have listed here, but I did this with no DLC. Some DLC items are OP.

If Goku's power level increases at the same rate till the end of DBGT as it does till the end of the Frieza saga, as a SS4 Goku would have a PL of roughly 939 Quinoctogintillion. For reference that is a 260 digit number. A PL of 14,600 is required to destroy an earth sized planet. There are about 2 nonillion earths worth of mass in the universe. That means SS4 Goku can destroy the universe about 32 Octosexagintillion times over. There's a reason they made Goku a god at the end of GT.

recently started up a new game again on nightmare. Doing it before and got as far as the Landsmeet before i just went onto doing other things lol.
Current game up to redcliff castle yeah i know its not far. My party setup goes like this:

I like to play the healer on nightmare, call it a little ocd but i like my character being the one in charge of healing, i also have some minor cc abilities to help more in fights such as winters grasp and cone of cold.

I have allistair setup purley to sit there and take a beating

Morrigan is setup for lots of damage, ie the vunerablity hex and death cloud combo. Hex makes every hit a critical combined with the cloud leads to some crazy damage and tears enemies apart.

I like the mabari for the beastly stun it has and also the overpower ability does a nice chunk of damage.

Its not that hard if you have the right Party with the right specc. Try the Arcane-Warrior Build - its extremly overpowered. You can wear all the Heavy Armor but still have Spells and get massive Resistance and Defense. My party died alot but I always killed everything witht that specc.

Arcane Warrior is definitely the most OP in the game, but it has a long ramp up period where you don't have the Gear/Talents to make it worthwhile until you are at least halfway through the game. Once all the pieces fall in place though, you are basically unstoppable. There is also a weapon (I forget the name) that is best suited for the Arcane Warrior. I can't for the life of me remember what is was though. It might be the crafted sword from that Star Ore, or maybe it was from Ascension.